In order to facilitate processing of fragile substrate (e.g., thin silicon wafers on a tape frame) with high pressure sprays, a backside support plate is desirable. However, this creates a problem when incoming wafers are already wet, as any liquid trapped between the backside of the wafer and the support plate cannot be rinsed off. There is therefore a desire to provide an assembly/mechanism by which liquid trapped between the backside of the wafer and the support plate can be avoided.